Stop devices for well conduits



'Feb. 3, 1959 Rfc. BAKER 2,

' STOP DEVICES FOR WELL CONDUITS Filed July 180, 1956 IN VEN TOR.

United States Patent STOP DEVICES FOR WELL CONDUITS Reuben C. Baker, Coalinga, ECaliizZ, assignor to Baker Oil Tools, Inc., Los Angeles, Calif., a corporation of California Application July 20, 1956, Serial bio/599,192

9 Claims. (.Cl. 166-441) with the casing string occurs as a result of their engagement with one or more stop device's attached to the. casing string. Securing of a stop "device to the casing string has' heretofore been achieved by welding or other modes of attachment, which have certain pronounced disadvantages. Welding is a time consuming and relatively costly 0peration, which has the further undesirable result of adversely affecting the physical characteristics and heat treatment of the well casing, particularly when the casing is made ofcertain alloy steels. Mechanical attaching of the stop device to the casing has heretofore suffered from'the defect of the stop device being incapable of withstanding sufi'lcient force before slipping on the well casing. Such stop devices are also relatively expensive and difiicult to mount properly on the casing.

Accordingly, it is an object of the present invention to provide a stop device adapted to be secured to the exterior of a running-in string, such as a tubular conduit string, without resorting to welding, and which is capable of withstanding heavy loads without slipping on the running-in string.

Another object of the invention is to provide a stop 'device for mounting on a running-in string, such as a conduit string, which is capable of withstanding heavy loads, is simple in construction, easy to assemble on the casing, and economical to manufacture. 'More specifically, the stop device is capable of transmittingheavy loads in both longitudinal directions in the well bore.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of aform in which it may be embodied. This form is shown in the drawings accompanying and forming partof the present specification. It

Patented Feb. V3, 1959 Fig. 4 is an enlarged fragmentary section taken along the line 4-4 on Fig. 2.

The specific device A illustrative of the invention, and disclosed in the drawings, is particularly designed for use fior moving apparatus B in a well bore C that is slidably mounted on a well casing D. As specifically shown, the device constituting the specific example of the invention is shown in connection with a casing centralizer B mounted on the string of well casing C. It is to be understood,however, that such device is also useful in other relationships, being adapted for engagement with wall scratchers, cementing baskets, and other apparatus mounted on a casing, or similar conduit or running-in string, to be moved longitudinally through the well bore with such running-in string, as well as being supported on the latter.

As shown in the drawings, the casing centralizer B is mounted on a casing section 10 disposed in the well bore. The centralizer can take any desired form. The one particularly shown includes upper and lower longitudinally spaced collars 11, 12 slidable on the casing section, which are interconnected by circumferentially spaced, out- 'wardly bowed leaf spring members 13, welded or otherwise suitably secured to the upper and lower collars. The springs 13 engage the wall of the well bore C and tend to center the well casing D therewithin.

Upper and lower stop rings 14, 15 are secured in longitudinally spaced relation to the upper and lower collars 11, 12, respectively, as through use of circumferentially spaced and longitudinally extending rigid bars 16 that are attached to both the collars 11, 12 and the rings 14, 15 in any suitable manner, as by a welding operation.

The particular centralizer B disclosed is of the hinge type, in which the collars and rings are each formed of two parts secured to one another by diametrically opposed hinges 18. The hinges on one side of the device may be disconnected by removing the hinge pins 19, which then allows the casing centralizer to be swung to open position and placed laterally around the casing section 10, whereupon the centralizer can be closed and the pins 19 reinserted through the hinge knuckles 20, all in a known manner.

The'centralizer apparatus B is movable longitudinally through the well bore upon longitudinal movement of the casing D. A stop device A is secured to the casing section It) between the upper and lower stop rings or collars 14, 15, such-device being engageable with the inner ends 21, 22 of the rings to force the centralizer apparatus through the well bore. The stop device A is operative to move the centralizer device when the casing string 'is shifted in both an upward direction and a downward will now be described in detail, for the purpose of illus- I trating the general principles of the invention; but it is to be understood that such detailed description isnot to be taken in a limiting sense since the scope of the in vention is best defined-by the appended claims.

Referring to the drawings: t

Figure l is a side elevation, with parts broken away, of apparatus embodying the invention mounted on a well casing section;

Fig. 2 is an enlarged side elevational View, with parts broken away, of the stop device shown in Fig. I mounted .on a casing section;

Fig. 3 is a view similar to Fig. 2 disclosing the .stop

.. device inanother operative position;

direction. When the casing D is moved in an upward direction, the stop device A is engageable with the lower end 21 of the upper stop ring 14 to pull the apparatus and its outwardly bowed springs 13 through the well bore and past any restrictions that might be encountered therein. Conversely, rnovernentof the casing string in a downward direction will cause the stop device 1}, to engage the upper edge 22 of the lower stop ring 15 and pull thece'ntering device B in a downward direction with the casing string D within the well bore C. Although the stop device A to be specifically described herein is capable of operations in both longitudinal directions, the invention contemplates the provision of a stop device that is capable of operation in a single direction only, if

desired.

preferably a cylindrical outer wall or periphery 27. The

ring terminates in an upper side 28 that makes an angle other than a right angle with the axis X of the sleeve 25, and it also terminates in a lower side 29 that may, for convenience of manufacture, be parallel to the upper side 28, and which also makes an angle other than a right angle to the axis of the sleeve. Such an arrangement will provide an uppermost point of contact 30 on the ring at its upper side 28 and a lowermost point of contact 31 on the ring on its lower side, which is substantially diametrically opposite the uppermost contact point. Such uppermost and lowermost points of con- 7 tact 30, 31 are adapted to engage the upper stop ring 14 and lower stop ring 15 of the centralizer, respectively, as pointed out hereinbelow, to eflect a gripping and coupling of the stop ring or sleeve 25 with the exterior of the well casing section 10.

The upper and lower sides 28, 29 of the stop ring or sleeve 25 are disposed in planes inclined to the axis of the sleeve to provide the uppermost and lowermost contact points 30, 31, since the two points can thus be provided in a comparatively inexpensive manner merely by cutting the ring 25 from tubing of the proper inside and outside diameters at an angle, the cuts being made with a saw. As an example, the upper side 28 and lower side 29 may be cut at an angle of about ten degrees to a plane normal to the axis of the ring or sleeve, thereby producing the uppermost and lowermost contact points 39, 31. Such diagonal cutting of the ring also provides a lower inner gripping edge 32 on one side of the ring below the uppermost point 30, and an upper gripping edge 33 on the ring above the lowermost point 31, these gripping edges being located at the intersections of the lower and upper sides 29, 28 of the ring and the inner cylindrical wall 26 of the ring.

When the ring 25 is mounted on a casing section, it is adapted to be rocked thereon, normally occupying the position disclosed in Fig. 1, in which its cylindrical wall 26 is parallel to the axis of the casing D. When rocked on the casing, as in a counter-clockwise direction (as shown in the drawings), the lower gripping edge 32 is caused to dig in a downward direction into the periphery of the casing 16, and the upper gripping edge 33 is adapted to dig in an upward direction into the periphery of the casing, thereby tenaciously coupling the ring 25 to the casing.

As disclosed, the rocking action is performed by permitting the ring 25 to pivot on the casing section about an axis Y normal to the axis X of the casing and displaced substantially 90 from the uppermost and lowermost Contact points 30, 31 and the upper and lower inner gripping edges 33, 32.. Such pivotal action is secured by providing diametrically opposed threaded holes 35 in the ring into each of which is threadedly disposed a headless set screw 36 having a non-circular outer socket 3'7 and an inner cup point 38. When each set screw 36 is tightened in the stop ring or sleeve 25 to cause its cup point 38 to grip the periphery of the casing section 10, bodily displacement of the stop sleeve along the casing section is prevented. However, the stop sleeve 25 can pivot on the casing section about the common axis Y of the set screws 36 between the approximate position disclosed in Fig. l, in which the gripping edges 32, 33 are out of contact with the periphery of the casing section 10, to the gripping position disclosed in Fig. 2, in which the upper and lower gripping edges 32, 33 are anchored in the periphery of the casing section.

The stop device A is mounted on the casing section 10 at the desired location by means of the set screws 36, and the casing centralizer B is then mounted transversely on the casing section 10 with the inner stop ring 14 disposed above the stop device A and the lower stop ring arranged below the stop device. The casing centralizer is closed and secured in closed position by inverting the hinge pins 1? in the respective hinge knuckles 20. The

effective over-all distance between the lowermost and uppermost points 30, 31 on the stop device is substantially less than the distances between the upper and lower stop rings 14, 15 of the centralizer device, to permit the casing D to move to some extent without causing engagement of the stop device A with either the upper or lower stop ring 14 or 15 of the casing centralizer. Prior to downward movement of the casing D in the well bore C, the stop device A occupies the general position disclosed in Fig. 1, in which the upper and lower inner gripping edges 33, 32 may be out of contact with the periphery of the well casing. As the casing moves down in the well bore, the lowermost point 31 of the stop device will move against the inner surface 22 of the lower stop ring 15 of the centralizer. In view of the resisting force of the springs 13 against the wall of the hole C, such engagement will at first cause the stop sleeve to pivot about the common axis Y of the set screws 36 until the upper inner gripping edge 33 and the lower inner gripping edge 32 engage the well casing, as disclosed in Fig. 2. The force transmitted between the stop sleeve 25 and the lower stop ring 15 tends to cause the gripping edges 32, 33 to dig into the periphery of the casing and thereby effectively couples the sleeve 25 to the casing. The greater the force being transmitted between the ring 25 and the centralizer B, the greater is the gripping action of the inner edges 32, 33 against the periphery of the casing section 10.

If, instead of the casing D being moved downwardly in the well bore C, it is now moved upwardly, then the force on the stop sleeve or ring 25 may be released,

whereupon it could return to its original position with its gripping edges 32, 33 out of contact with the well i casing. Regardless of whether or not the gripping edges are released, upward movement of the casing will cause the'uppermost point 30 on the stop sleeve to engage the inner side 21 of the upper stop ring 14 of the centralizer, rocking the stop sleeve 25 about the common axis Y of the screws 36 in a counter-clockwise direction, as disclosed in Fig. 2, to swing the lower gripping edge 32 downwardly into gripping engagement with the periphcry of the well casing section 10 and the upper gripping edge 33 upwardly into gripping engagement with the periphery of the casing. If such edges 32, 33 have retained their gripping position as a result of downward movement of the casing, then the engagement of the uppermost point 30 of the sleeve with the upper stop ring 14 of the centralizer will maintain such gripping engagement. Here again, as the force transmitted between the uppermost point 30 on the stop sleeve 25 and the upper stop ring 14 of the centralizer increases, the sleeve 25 tends to grip the periphery of the casing section 10 more firmly.

Theoretically, the gripping edges 32, 33 could dig into the casing to an extent limited by the upper or lower sides 28, 29 of the sleeve 25 assuming a position normal to the axis X of the casing, at which time such upper or lower side will be making flush engagement with the upper or lower stop rings 14 or 15 of the casing centralizer. Further increase in the gripping force, therefore, could not occur. However, the apparatus is preferably designed so that such right angular relationship of the upper and lower sides 28, 29 to the casing axis X will not be achieved, but even if achieved, the gripping edges 32, 33 have dug into the periphery of the casing so tenaciously that the stop ring 25 will remain anchored to the well casing and capable of transmitting a very great longitudinal force.

It is, therefore, apparent that by virtue of the rockable pivotal arrangement on the annular stop member 25 of the casing, to pivot its gripping edges 32, 33 into engagement with the periphery of the well casing, a strong and effective stop device has been provided which eliminates the need for welding the ring 25 to the casing, and which provides a very simple stop structure capable ably mounted on the casing, in both longitudinal directions of movement of the well casing in the well bore. The inventor claims:

1. In a stop device adapted to be mounted on a tubular running-in string to be lowered in a well bore: an annular member adapted to be disposed around the exterior of the running-in string and having an inner wall substantially greater 7 in internal diameter than the external diameter of the running-in string; means on said member adapted to engage the exterior of the running-in string on opposite sides thereof for rockably mounting said member on the running-in string; said member having a grip ping portion thereon adapted to grip the running-in string when said inner wall is inclined to the axis of the runningin string; said member having means thereon adapted to engage an apparatus on the running-in string to rock said member on the running-in string to a position in which its inner wall is inclined to the running-in string and bring said gripping portion into gripping engagement with the runnng-in string.

2. In a stop device adapted to be mounted on a tubular running-in string to be lowered in a well bore: an annular member adapted to be disposed around the exterior of the running-in string and having an inner wall substantially greater in internal diameter than the external diameter of the running-in string; means on said member adapted to engage the exterior of the running-in string on opposite sides thereof for rockably mounting said member on the running-in string; said member having a gripping portion thereon arcuately displaced from the rocking axis of said member and adapted to grip the running-in string when said inner wall is inclined to the axis of the running-in string; said member having means thereon arcuately displaced from the rocking axis of said member and adapted to engage an apparatus on the running-in string to rock said member on the running-in string to a position in which its inner wall is inclined to the running-in string and bring said gripping portion into gripping engagement with the running-in string.

3. In a stop device adapted to be mounted on a tubular running-in string to be lowered in a well bore: an annular member adapted to be disposed around the exterior of the running-in string and having an inner wall substantially greater in internal diameter than the external diameter of the running-in string; an element adjustably threaded on said member and adapted to grip the runningin string to pivotally mount said member on the runningin string; said member having a gripping portion thereon adapted to grip the running-in string when said inner wall is inclined to the axis of the running-in string; said member having means thereon adapted to engage an apparatus on the running-in string to pivot said member on the running-in string to a position inwhich its inner wall is inclined to the running-in string and bring said gripping portion into gripping engagement with the running-in string.

4. Ina stop device adapted to be mounted on a tubular running-in strip to be disposed in a well bore: an annular member adapted to be disposed around the exterior of the running-in string and having an inner wall substan-v tially greater in internal diameter than the external diameter of the running-in string; an element adjustably v threaded on said member and adapted to grip the runningin string to pivotally mount said member on the runningin string; said member having a gripping portion thereon arcuately displaced from the pivot axis of said member and adapted to grip the running-in string when said inner wall is inclined to the axis of the running-in string; said member having means thereon arcuately displaced from the pivot axis of said member and adapted to engage an apparatus on the running-in string to pivot said member on the running-in string to apo'si'tion in which its inner wall is inclined to the running-in string and bring said gripping portion into gripping engagement with the running-in string.

5. In a stopdevice adapted to be mounted on a tubular running-instring to be lowered in a Well bore: an annular member adapted to be disposed around the exterior of the running-in string and having an inner wall substantially greater in internal diameter than the external diameter of the running-in string; means on said member 'adapted to engage the exterior of the running-in string on opposite sides thereof for rockably mounting said member on the running-in string; said member having a gripping portion thereon adapted to grip the running-in string; one end of said member lying in a plane inclined to the axis of said member to provide a portion adapted to engage an apparatus on the running-in string to rock said member on the running-in string and bring said gripping portion into gripping engagement with the running-in string.

6. In a stop device adapted to be mounted on a tubular running-in string to be lowered in a well bore: an annular member adapted to be disposed around the exterior of the running-in string and having an inner wall substantially greater in internal diameter than the external diameter of the running-in string; means on said member adapted to engage the exterior of the running-in string on opposite sides thereof for rockably mounting said member on the running-in string; said member having a gripping portion thereon arcuately displaced from the rocking axis of said member and adapted to grip the running-in string; one end of said member lying in a plane inclined to the axis of said member to provide a portion arcuately displaced from the rocking axis of said member and adapted to engage an apparatus on the running-in string to rock said member on the runningin string and bring said gripping portion into gripping engagement with the running-in string.

7. In a stop device adapted to be mounted on a tubular running-in string to be lowered in a well bore: an annular member adapted to be disposed around the exterior of the running-in string and having an inner wall substantially greater in internal diameter than the external diameter of the running-in string; diametrically disposed elements adjustably threaded on said member and adapted to grip the running-in string to pivotally mount said member on the running-in string; said member having a gripping portion thereon adapted to grip the running-in string; one end of said member lying in a plane inclined to the axis of said member to provide a portion arcuately displaced from the pivot axis of said member and adapted to engage an apparatus on the running-in string to pivot said member on the running-in string and bring said gripping portion into gripping engagement with the running-in string.

8. In a stop device adapted to be mounted on a tubular runningin string to be lowered in a well bore: an annular member adapted to be disposed around the exterior of the running-in string and having an inner wall substantially greater in internal diameter than the external diameter of the running-in string; diametrically disposed elements adjustably threaded on said member and adapted to grip the running in string to pivotally mount said member 'on the running-in string; said member having substantially diametrically opposed upper and lower gripping portions thereon adapted to grip the running-in string; the upper and lower ends of said member lying in planes inclined to the axis of, said member to provide upper and lower portions arcuately displaced from the pivot axis. of said member and adapted to engage apparatus on the running-in string to-pivot V said member on the running-in string and bring said grip- 9. In a stop device adapted to be mounted on a tubular running-in string to be lowered in a well bore: an annular member adapted to be disposed around the exterior of the running-in string and having an inner wall substantially greater in internal diameter than the external diameter of the running-in string; diametrically opposed threaded elements adjustably threaded on said member and adapted to grip the running-in string to pivotally mount said member on the running-in string; the upper and lower ends of said member lying in planes inclined to the axis of said member to provide upper and lower gripping edges at the inner wall of said member areaately displaced from the pivot axis of said member and also to provide upper and lower portions adapted to engage apparatus on the running-in string to pivot said tmember on the running-in string. and' bring said upper UNITED STATES PATENTS Rogers Jan. 3, 1933 Kluck Apr. 28, 1953 

